1. Field of the Invention
The present invention relates to an image forming apparatus and a power supply method for the same.
2. Description of the Related Art
Recent advances in technology have provided image forming apparatuses with a wide range of features comparable to personal computers. For example, image forming apparatuses can now print data received from other apparatuses via a network, or even store the data therein. However, if a power cut occurs (i.e., commercial power supply is interrupted) while an image forming apparatus is receiving data, the data may be lost. Besides, if a power cut occurs while an image forming apparatus is in the process of forming an image, driving mechanisms become out of control and may be damaged.
Japanese Patent Application Laid-open No. 2005-148581 discloses a conventional image forming apparatus that includes a power-cut detecting circuit and an auxiliary power supply. The auxiliary power supply basically supplements power supplied to a fixing heater. However, when the power-cut detecting circuit detects a power cut, the auxiliary power supply supplies power to each unit of the image forming apparatus under control of its control unit.
In the conventional image forming apparatus, however, because the control unit itself requires power supply to operate, it can not operate when there is power cut. Consequently, there is a need to prepare a power supply unit that is capable of supplying power, at least for a predetermined time, after a power cut occurs, resulting in structural complexity of the power supply unit. Moreover, if the auxiliary power supply fails to supply power in time, power supply becomes unstable, which causes data loss, damages to driving mechanisms, and the like.